Jumping on and off boxes is one of the best plyometric exercises to improve leg power, speed, and strength. Each box is constructed of 1_x001d_ square steel tubing. Top platform is steel reinforced 1\/4_x001d_ aluminum covered with a rubber surface. Anti-skid rubber is located at base corners to prevent slipping and to protect floors. Tapered design allows for much greater stability, and easy stacking for storage.